Inkjet printing devices, such as plotters, facsimile machines and inkjet printers, print images using ink. These printing devices are provided with ink cartridges, often called “pens,” for ejecting drops of ink onto a sheet of print media. Each ink cartridge has an ink reservoir and a printhead with a plurality of small nozzles through which the ink drops are ejected. Because printing consumes the ink in the ink cartridge, the cartridge must be replaced or refilled when the cartridge is out of ink. Some users simply buy new ink cartridges when the cartridges are emptied. Ordering a new cartridge from the manufacturer may be expensive, time consuming and inconvenient. Some other users attempt to refill the empty cartridge with a new supply of ink using cartridge refilling kits. However, these cartridge refilling kits are often messy. Furthermore, the users may incorrectly fill the cartridge with the wrong ink or attempt to use the cartridge beyond its useful life. Incorrect refilling and using an ink cartridge that is beyond its useful life lead to unsatisfactory printing output and/or damage to the printing devices.